There is provided a sheet processing apparatus capable of preventing the roll sheet cut by the cutting device from falling over to the sheet processing apparatus and improving the conveyance capability of the roll sheet when the long size roll sheet is made. Long size roll sheet is fixed at three spots, wherein the three spots are the top edge portion of the roll sheet receiving portion, the top edge portion on the downstream side of the regulatory member, and the bottom edge portion of the projecting portion. The bottom edge portion of the projecting portion is constructed to be always located inside a circular arc which starts from a center O with a maximum radius R of the roll sheet, wherein the circular arc passes the top edge portion of the roll sheet receiving portion and the top edge portion on the downstream side of the regulatory member.